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You are here:Home » Antibodies » Antibodies-Protein S » Anti -Protein S

Anti -Protein S


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Clone Host Grade Applications
Polyclonal Sheep Affinity Purified E
Protein S is a vitamin K-dependent, potent neutral anticoagulant plasma glycoprotein. Protein S has a molecular weight of approximately 70kD and concists of a single polypeptide chain. The concentration of protein S in human plasma is 25ug/ml, with a half-life of approximately two days. About 40% of Protein S in plasma is in a free form, whereas 60% is complexed with C4b-binding Protein (C4BP). Only the free Protein S functions as a cofactor to antigen presenting cells (APC) in the APC-dependent degradation of Factor Va and Factor VIIIa.
Catalog #P9108-09
Protein S is thought to function in both the coagulation and complement cascades. It has been suggested that g-carboxyglutamic acid (gla) dependent binding of protein S to negatively charged phospholipids may function to concentrate C4BP at cell surfaces following injury.
In the coagulation system, Protein S functions as an anticoagulant cofactor protein. Activated Protein C (APC) forms a 11 stoichiometric complex with Protein S in the presence of Ca2+ and phospholipid vesicles (Kd=6x10e-9M). In the presence of Protein S, a moderate increase (3-10 fold) in the rate of factor Va and factor VIIIa inactivation by APC is observed in plasma and on the surface of unstimulated platelets. Protein S bound to C4BP does not possess APC cofactor activity. Recently, an additional binding protein which enhances the activity of Protein S has been described. Proteolytic inactivation of Protein S by thrombin has been proposed as a regulatory mechanism in this system. A single cleavage by thrombin abolishes Protein S cofactor activity by removing an NH2-terminal peptide (Mr=8000) which contains the gla domain.
The domain structure of Protein S is similar to that of the other vitamin K-dependent coagulation factors with the exception that Protein S does not possess the catalytic triad. Protein S is a single chain protein containing 10 gla residues in the NH2-terminal domain and 4 epidermal growth factor (EGF) domains.
ApplicationsSuitable for use in Immunoelectrophoresisas and ELISA for Protein S. Other applications not tested.
Recommended DilutionELISA: capture
Optimal dilutions to be determined by the researcher.
Storage and StabilityMay be stored at 4°C for short-term only. For long-term storage, store at -20°C. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
Clone TypePolyclonal
FormSupplied as a liquid in 0.01M HEPES, pH 7.4, 0.15M sodium chloride and 50% glycerol. No preservatives are added.
PurityPurified by immunoaffinity chromatography.
ImmunogenHuman Protein S (PS) purified from plasma.
SpecificitySpecific for human Protein S.
Important NoteThis product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.

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